The present disclosure generally relates to downhole fluid flow control and, more particularly, to flow distribution assemblies used to distribute fluid flow into surrounding subterranean formations.
In the course of completing wellbores that traverse hydrocarbon-bearing portions of subterranean formations, it is oftentimes desirable to inject fluids into the wellbore for a number of purposes. For example, gases, such as steam, are often injected into surrounding formations in order to stimulate the production of high-viscosity hydrocarbons. In other applications, a treatment fluid, such as hydrochloric acid is injected into the wellbore to react with acid-soluble materials disposed in the formation, thereby enlarging pore spaces in the formation. In yet other applications, fluids, such as water or gas, may be injected into the surrounding formations in order to maintain formation pressures so that a producing well can continue production.
Injection operations are typically carried out by introducing an injection string into a wellbore to a desired location where fluid injection is desired. The injection string oftentimes includes a wellbore screen assembly that includes one or more sand screens arranged thereabout. The fluid injected into the surrounding formation must first pass through the sand screens, which serve to prevent the influx of sand or particulates back into the injection string during temporary breaks in the injection operation. Injection of the fluid typically occurs at high flow rates, which can lead to the erosion of vital portions of the sand screens at discrete exit points in the sand screens closest to the source of the fluid entrance point, such as a sliding sleeve within the injection tubing. Over time, fluid flow through the sand screens at these exit points can cause the sand screens to erode or otherwise degrade, and thereby render the filtering capabilities of the sand screen ineffective.
Moreover, following an injection operation, injection strings can optionally be used for production operations by reversing the flow of fluids and drawing fluids into the injection string from the surrounding formations. During such production operations, the sand screens, if undamaged, can be valuable in filtering sand, proppant, and any wellbore particulates of a certain size from being entrained into the injection tubing. However, similar to an injection operation, the influx of fluids also penetrates the sand screens at high flow rates and at discrete locations along the sand screens, such as at or near the sliding sleeves. If the sand screens are damaged, the high flow rate of incoming fluids again makes the sand screens susceptible to increased damage and erosion at vital portions during production operations.